This project represents a completion of our major longitudinal study of a general population (The Tucson Epidemiological Study of Airways Obstructive Diseases). The sample was originally enrolled starting approximately 17-18 years ago, the eleventh survey of the population has been recently completed. A very large and diverse data base has been accumulated on the greater than 1650 Tucson households containing greater than 4,500 subjects participating in the study. The major aims of this project continue to be the determination of the pathogeneses, natural histories, methods of early detection, and means of prevention of airways obstructive diseases (AOD). Most of the work will be completed for the 20 years of follow-up of the population which was envisioned in the initial study design, it is planned to follow specific subgroups of special interest within the new grant period of this project. This emphasis reflects the findings: pre- asthmatic and asthmatic conditions need further study, as do other influences in infancy, childhood and adolescence. Further studies include completing immunological and physiological studies in those enrolled as infants during the study, and further genetic studies. The study will continue to involve expertise from many disciplines including epidemiology, biostatistics, physiology, immunology, and clinical science in order to provide a multi-disciplinary approach to the study of AOD. New analyses will be emphasized, it will evaluate the incidence of new symptoms, disease, and functional impairment as well as mortality in relationship to initial characteristics of the subjects, host risk factors, exposure to provocative factors and changes in these exposures, and the course of findings early in the study. Newly developing clinically significant AOD cases will continue to be identified and studied in detail in collaboration with P2 and other SCOR projects. By determining the interactions of host and environmental factors in determinants of symptoms and physiological status over 20 year age segments beginning at birth, the data from this study will allow one to "piece together" the evolution of both persistent and reactive airways diseases from early childhood, demonstrating sequence of events finally leading to clinically significant AOD. The risk factors being studied include early childhood respiratory illnesses, evidences of an atopic predisposition, signs and symptoms suggesting bronchial reactivity, protease inhibitor status, genetic background, gender, age, respiratory infections, and early exposure to potential bronchial irritants.